Process for the manufacture of mercury oxid.



APPLIQATION EILED JAN. 30. 1919.

Patented Apr. 8, 1919.

' Invturoa: EIV\\L Ku u N mi W4 ansrarus PATENT ornrcn.

nun. KUHN, or BasnL, SWITZERLAND;

rnocnss Fort THE MANUFACTURE or 'mnncumr oxrn.

1,299,581. Specification of Letters Patent. t t -,3, 1919 Applicationfiled January 30,1919. Sefla1No.274,0 83'.

To all whomit may-concern: the dimension requested by the volume of Beit known that I, Dr. EMIL KUHN, a the oxidproduced in an operation, sothat citizen of the Swiss Republic, and resident the transformation ofvery large quantities of Basel, Switzerland, have invented a new can beeffected in a smallroom easy to con- 5 and useful Process fortheManufacture of trol, Fourthly no other materials than mer- Mercury Oxid,of which the following is a cury and oxygen are employed and fifthlyfull, clear, and exact specification. the apparatus can be formedby ironin op- Heretofore the preparation of mercury position to the workingwith aqueous nitric oxid was obtained by 'electrolyz'ing alkaline acid.v

.0 solutions with mercury anode or by dissolv- The drawing illustrates asimple form of ing metallic mercury in acids and precipiapparatus forperforming the process.

.tating the mercury oxid from the solution Example: Mercury isinstilled, by drops,

obtained by means of alkalis or by the com-' in the iron vessel 1 of theapparatus reprebustion of mercury with air or oxygen. sented by a partlysectional elevation in the 15 The two first processes have theinconaccompanying drawing, filled about to the venience that owing tothe solubility of the middle with liquid N 0 while oxygen or air mercuryoxid in,water, which is not to be is introduced simultaneouslyin thevessel.

neglected, losses occur which can only be The attack of the mercuryoccurs accordavoided partly 'by complicated provisions. ing to thefollowing formula:

20 These losses-are also increased by the facts 2 that the intermediaryproducts must be sub- I j eted to various i ul tio as ro ub The vesselis provided with a. reflux cooler,

v sions, precipitations, out-washings and the in order to let dropretrograde the N O, lik vaporized by the reaction heat. Obviously 25 Theoxidation of mercury by oxygen bethe mercury can be placed in the vesseland gins at temperatures above 300 0., but prothe N 0, introduced bydrops in the latter.

'ceeds then very slowly. At higher tempera- After completetransformation of the mertures, the oxygen pressure of mercury oxid iscury into nitrate, the reflux cooler is set out already perceivable, asit is shownby the of service and the excess of N O 'remaining in- 30equilibrium essays of P. Laban (Uompte the vessel 1 driven over in asimilar vessel Remius 1899, vol. 128, page 825) therefore 2. Hereafterthe content of the vessel 1 is the oxidation cannot be complete in thisheated, preferably while stirring slowly, latter case. But. for thetechnical manuwhereby the mercury nitrate is decomposed facture ofmercury oxid the slow formation according to theformula V 35 at lowtemperatures is equally disadvanta- H (N0 -:2HgO-1-2NO.,.

geous as the incomplete union of. mercury and oxygen at" highertemperatures, setting The N0 evolved in the vessel 1'- is colaside theother inconveniences inherent to le ted-as -l T O 1n the secondvessel 2.T ve A rocess'working with mercury apor, HgO obtained 1S dustfine, needsconsequently" I,

'40 The following process 1s also based on an 110 g g and 1S h m e v ypu oxidation ofmetallio mercury by gases con- Then the yessel 1 isreplaced byanother 'or taining oxygen, but is distinguished h by. 1tsHgO'JS discharged therefrom and the that the oxidation by gasesvcontaming oxysame process is repeated, the vessel 2 taking en isefifeeted'with the aid of dry nitrogen up now the functions of thevessel 1 vessel 4 5 oxids acting as oxygen transmitters. 1 now servingto receive the N0 expelled The advantages of the process are the fromvessel 2. One can obviously also pr0- following: ceed in the manner,thatfthe N 0; collected- The attack of the metallic mercury occurs inthe vessel 1, by means of compressed air at a temperature, atwhich itsvapor pressure and mercury is again instilled by'drops in the 60 isstill very small, for instance at ordinary vessell', etc. The processdoes not change, if

room temperature. Secondly the react on the supply ofoxygen is, 1n thecourse 0 the mass can remain in a closed vesselodurmg decomposition,intentionally or accidentally the wholeprocess that is to say until theinsuflicient-for the quantitative retroformaa I metallic mercury 1stransformed nto the tion of NO NO is then formed, which dis- 65 achieveddus -fine oxid, so that all mercury solves 1n the N 0 contained in thevessel losses are excluded. Thereby the necessary 2, forming 0 which canalso be oxidized apparatus has only to be some greater than eas ly to N0, 'by introducing oxygen, as

vsists in the possibility well before as during the treatment of a freshquantity of mercur 'When oxygen is employed for the oxida: tion -thereexists theoretically no sources of losses neither for Hg nor fornitrogen oxid. In this manner with a very small quantity of N 0technically very large quantities of mercury can be combined withoxygen, without any consumption of essential quantities of the auxiliarybody and without any inanipulation of the intermediary products outwardof the apparatus. The N acts only as oxygen transmitter.

A special advantage of this process conof its application for thetransformation into mercury oxid of -inercury wastes as they result forinstance from the synthesis acetylene.

What I claim is:

The herein described proces for the manufacture "of mercury oxid byoxidation of metallic mercury, wherein the oxidation by gases containingoxygen is effected with the aid of dry nitrogen oxids acting as oxygentransmitters.

In witness whereof I have hereunto signed my name this 2d day ofDecember, 1918, in the presence of two subscribing witnesses.

DR. EMIL KUHN.

of organic bodies from Witnesses H. H. DICK, ARNAUD Rrrrnn.

